U.S. Intell Chief: Source of Cyber Attacks Still Unknown

U.S. authorities have not determined who was behind the recent cyber attacks that temporarily knocked some federal Web sites offline, the country's top intelligence official said Wednesday.

Dennis Blair, the director of national intelligence, said officials have not learned who carried out the attacks that hijacked tens of thousands of computers around the world. Affected computers sent out massive amounts of information to overwhelm systems, which shut down government sites in the United States and South Korea.

Blair said the government is working with partners in other nations to compare data to determine who was behind the attacks, which he called a "relatively unsophisticated botnet-type attack."

After the attacks, initial press reports said South Korean intelligence authorities suspected that North Korea or its supporters were involved. However, security experts have said that definitively identifying who is behind the cyber attacks might be difficult, if not impossible.

In March, Blair told reporters that improving authorities' abilities to attribute cyber attacks was a high priority.

"The reason that it's taking as long as it has is that like most Internet attackers, the person who perpetrated this attack went through a series of cutouts, different [Internet protocol addresses], and the process of going back and sorting that out just takes some time," Blair said after a speech at the U.S. Chamber of Commerce in Washington.

However, Blair said information about the system vulnerabilities that made the attacks possible was shared quickly to make sure others were protected.

In addition, Blair said it's important to improve information sharing and warnings about cybersecurity vulnerabilities. He also said the United States needs to bolster its efforts related to the negotiation of the international cybersecurity standards, protocols and agreements.